I never lock my 2000 540i when in the garage, yet I have two bmws and because of their JUMBO keys being on the same key chain, I can only assume that when detailing or working around them one key somehow smashes into another in my jean pocket and is always setting off the panic alarm on the 540. I mean, at other times I might be poking around and I notice that I accidentally unlock one of the trunks or lock a car, but what a pain when at work and I bend down to pick up something and the keys get snug in my pocket and next thing I know the panic alarm is going off. Which combination of buttons is likely the easiest to get pushed in and alarm sets off? I assume it is the panic as the car is often not locked when this happens. Can the panic feature be defeated?